### Enhancements

* Add reusable `http_test_server` fixture to `conda.testing` module for serving mock conda channels and remote files in tests. Fixture uses standard `@pytest.mark.parametrize()` with `indirect=True` for configuring directories, supporting both pre-existing directories and dynamic content generation. Provides clean API with `get_url()` helper method and `directory` attribute. (#15528 via #15529)

### Bug fixes

* <news item>

### Deprecations

* <news item>

### Docs

* Add comprehensive guide for using HTTP test server fixture in `docs/source/dev-guide/writing-tests/http-test-server.md`. Includes usage examples, API reference, and troubleshooting tips. (#15528 via #15529)

### Other

* <news item>
